Heating molten electrolytes.



VTo allwhom it may concern.' Y i ;sTATEs PATENT OFFICE.

FRANZ yorxGELGEN, or HoLcoMEs Eocx, VIRGINIA, AND GEoEGE oULToN sEWAED, E EAST oEANGE, NEW JERSEY, AssIGNoEs To VIRGINIA LABonAToEY COMPANY, oF NEW YoEx, N. Y., A coEroEATIoN or NEW Yoan.

Beit known that we, FRANZ voN K- GELGEN, a subject of the German Emperor, residing at Holcombs Rock, in the county of Bedford and State of Virginia, and (SrEoRGE` OUL'noN SEWARD, a citizen 'of the United Statesv of America, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Heating Molten Electrolytes, of which the followingis a specification.

Our invention relates to a method of heat'- ing electrolytes in the'electrolysis' of fused salts and to an improved electrolytic cell adapted thereto.

It relates particularly to al method in which heat other than that supplied bythe electrolytic current is employed for maintaining the -molten electrolyte at the properV temperature and assisting the electrolytic current.

There are several methods .at present in use for heating electrolytes, each of which has certain disadvantages. The method of heating the electrolytic 'vessel by fuel ap-l plied externally has been generally abandoned because of the injurious eects on the vessel andfor other reasons. It has been attempted to effect the heating by conducting burning gases onto the surface of the electrolyte, but this has not been successful, and

has the disadvantage of contaminating the electrolyte.

The general practice at the present. time in the electrolysis of molten salts is to rely solely upon the current to perform both functions, heating and electrolysis, but certain advantages in economy of current and establishing proper relation Abetween temperaturel of the electrolyte and current density can be attained-by proper use of a supplementary source of heat. .p

The object of our invent'on is to. ac complish such supplemental heating with- ,out contaminating the electrolyte or injuring the electrolytic, vessel.

In the accompanying drawing, whichis a vertical section of an electrolytrc tank. or cell, showing the lprinciple of our InventIon,

the tank is made of a metal-shellv A lined with a material B not attacked by the electrolyte C. In the electrolyte are immersed l lemanan. D, and the cathode E, the lai-.ter

the cathode.

HEATING MOETEN ELETEoLY'TE's.

' Patented 1196.2, 1913.

here shown as hollowu On the `surface of the electrolyte floats the, separated vmetal F confined by the curtain G. rPhe hollow cathodel E is partially submerged in thel electrolyte and is provided with a pipe through which enters a burning gas, or a Inlxture of gas and air, for internally heating the cathode. The drawing shows a gassupply pipe J and an inlet K, so' that the Bunsen burner.

L is the pipe through which the gases pass out after, having accomplished the heating of the electrolyte through the hollow cathode.

We do not confine ourselves to heating the cathode only,'as we may heat the anode or the cathode or both, though generally heat suiiicient to replace that lost by radiation :from the furnace can be introduced through the heated cathode alone. In the case of the `manufacture -of' sodium we should use an iron cathode and a carbon anode, and we could'heat either one or both.

' In the drawing we have shown gas as the heating agent, but it is apparent that any other fuel may be used. It is not even neces'- sary to use the hollow electrodes as the heat- Ydevice may operate. on the principle of the l ing bodies, since separate heating bodies mayv v be used which can be replaced'without interrupting the current. By passing a small current through `such separate heating bodies they can be protected from any injurious action of the electrolyte.

.In large electrolytic vessels where the radiationlosses are not very great, the use, of our Invention may leave the electric current entirely free to effect electrolysis, the heating bodies replacing all the heat lost by radiation, removal of metal and salt, etc.

We are aware that Ait has been proposed in the electrolysis of aqueousv solutions to heat the electrolyte by a circulation of steam through a -coil of pipe lying against the outer wall of the vessel, and serving also as Such heating means would not be useful to attain the object of our invention, "namely, the maintenance of proper fluidity of the molten salt or compound serving as the electrolyte, and particu-V larly for the production of light metals such as sodium, which when separated float' as a molten pool on the surface of the electrolyte. In such electrolysis diiliculty is experienced in keeping the bath at utilizing the high heat of direct combustion within a body which itself is immersed in and surroundedby the molten electrolyte, i

ali'ords a means whereby the temperature and fluidity of the electrolyte may be controlled to 'a nicety, the heat'of combustion being use d merely to supplement the heat resulting from the current used for electrolysis.

Having thus fully set forth and illustrated our invention, what we claim is 'z- 1. An electrolytic cell havin a heating means comprising a hollow bo y immersed in the electrolyte, and means for heating the same by burning a combustible therein.

2. An electrolytic cell comprising a hollow electrode immersed in the electrolyte, and means for heating the same by burning therein a current of hot gas.

3. The method of supplementingthe heating effect of an electrolytic current, which consists in immersing in the electrolyte a hollow body and heating the same bybburning a combustible therein.

4. The method of supplementing the heating eiiect of an electrolytic current, which consists in immersing in the electrolyte a hollow electrode, and heating the same byv the combustion therein of a. current of ho gas.

5. -In the electrolysis of molten salts, sup plem'enting the heating eiiect .of the electrolytic current -by introducing into the electrolyte a hollow body and heating the latter by burning a gaseous combustible therein.

6. In the electrolysis of molten salts, supplementing the heating elect of the electrolytic current by introducing into the electrolyte a' hollow electrode, and heating the latter by burning a gaseous combustible therein.

7.- In the electrolytic production of light metals from molten salts thereof, supplementing the heating effect of the electrolytic cu'rrent by introducing into the electrolyte a hollow body, and heating the latter by burning a combustible therein.

In witness whereof, I have hereunto signed my name in the presence of two subscribing. witnesses.

' FRANZ voN KUGELGEN.

Witnesses:

JNO. M. OTEY, H. C. LIPPERT.

In witness whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

GEORGE OULTON SEWARD.

Witnesses:

CHARLES K. FRASER, 'lnoMAs F. WALLACE. 

